Stoker grate



July 31 G. W. EDWARDS STOKER GRATE Filed May 5, 1921 In W912 for eoig'eWfldwanw v Patented daily 3i, i923.

nnirao snares GEORGE W. EDWARDS, OF BERLIN, NEW HAMPSHIRE.

sronnn onn'r'n.

Application filed may 5, 1921. Serial No. 466,883.

To all whom it may concern:

Be it known that I, GEORGE W. EDWARDS, a citizen of the United States, and resident of Berlin, county of Coos, and State of New Hampshire, have invented an Improvement in Stoker Grates, of which the following is a specification.

In the construction of certain types of stoker grates, and more particularly that known as the Coxe stoker, the grates are formed of endless construction, comprising a plurality of transverse carrier bars secured at each end to sprocket chains by which they are connected and fed, said carrier bars each being provided with a dove- 1 tail portion upon which a plurality of keys, constituting the grate bar surface, are threaded and by which they are conveyed through the stoker formgin grate for a bed of coal. hese keys are each provided with lugs at their under sides, forming dove-tail jaws which snugly fits upon the dove-tail carrier bar, whereby said keys, constituting the grate surface, are re 'placeable and are easily assembled and dismantled, when required. On account of the rough usage and the varying heat strains to which the keys are subjected, it frequently happens that one of the jaws becomes broken and the key thereupon becomes loose and is liable to fall out, thereby introducing a defective conditioninto the grate. While the key sections per so are not expensive and are easily assembled when installing the stoker, nevertheless, when in operation, great loss and inconvenience would arise if it was necessary to stop the operation of the stoker for the purpose of dismantling one of the carrier bars'and associated keys for the purpose of replacing the broken keys, and it is to overcome this difliculty that my invention is directed.

The object of my invention is to provide a construction by way of repair which will enable the defective keys to be quickly replaced without the necessity of even stopping the travelling movement of the grate, it being possible for one man to replace a number of the keys on a single bar without stopping the Stoker; the construction of my improved keys being such that they may be uickly applied to-the dove-tail portion of t e bar and securely attached thereto by the single act of driving into position an adjustable portion thereon, as more fully pointed out hereinafter.

a travelling.

the dove-tail portion of the carrier bar, performing the function of the normal lug or aw which has been broken from the key required to be replaced. i

In 'practice, the engineer in charge of the stoker is furnished with a number of additional keys having my improved adjust.- able locking means which may be quickly introduced into the vacant positions from which the broken keys are removed and thereupon locked to the dove-tail portion of the carrier bar by the simple act of driving down a pin which is frictionally held in the repairing key and exposed through the bar or grate surface thereof.

My invention also comprehends details of construction which, together with the features above specified, are fully set out in the following specification ,and'more particularly illustrated in the accompanying drawings forming part thereof.

Referring to the drawings: Fig. 1 is a transverse sectional view of a portion of the Stoker gratevillustrating one of the carrier bars of a type known as the Coxestoker showing a number of the keys attached thereto for constituting the grate surface for directly holding the fire bed; Fig. 2 is a transverse sectional view of the same, showing mv improved key applied thereto (and a lug portion of the key beyond); Fig. 3 is a plan view illustrating the application of my improved key to the dove-tail portion of the carrier bar; and Fig. 4; is a sectional view showing a modification of my invention.

12 is the transverse carrier bar constituting one of the sections of the grate and is adapted, at each end, for connection with the sprocket chain (not shown). This carrier bar is provided along its upper portion with a dove-tail bar portion 2 extending the whole width of the carrier bar between the end or head portions thereof. The dove-tail ill lllll its bar portion 2 is held in position upon the carrier bar by means of bolts 13. The keys constituting the grate surface are indicated at 3 and 3 (Fig. 1), the normal keys 3 provided with downwardly extending lugs 5 and 6 forming between them dove-tail recesses, as will be understood by reference to Fig. 2. lit will, therefore, be understood that Fig. 2 is intended to represent a definitely constructed repairing key of my 1nvelition, but may also be taken as a representation of a normal key whose lug 6 is broken away and which has been modified to make it constitute my invention.

Referring-more specifically to the key, as

shown in Figs. 2 and 3 and embodying the special features of my invention, the under part of the key 3 is provided with one of the lugs 5 and with a surface 4 for respec tively engaging one of the dove-tail portions of the bar 2 and the top thereof, and which definitely positions the key thereon, and in relation to the remaining keys which may be in normal condition on the stoker. That portion of the key 3 that would have provided the additional lug 6 is omitted or broken away and there is provided an oblique hole 8 drilled downward through the key from the upper or grate surface 10 thereof and into which a hardened steel pin 9 is driven, so that its lower end 7 is rojected downward under the dove-tail o the part 2, and performs the functions for key 3 that are performed for key 3 by In 6. Tn Fig. 2, the part 6 is the lug on the adjacent key 3 beyond. It is manifest that the pin 9 should snugly fit the hole 8, so that it will not work through the same or fall out, and furthermore, it should be sufliciently held in position by friction that it remains in the upward position until positively driven downward by means of a hammer. In this manner the pin remains out of cooperation with the dove-tail portion 2 until the key has been placed in position, after which, the pin is forcibly driven down into the position shown. The key will then be permanently attached to the dove-tail portion of the carrier bar, 'ust as efiectively as the original key was held theredn by means of the lug 6.

lit is evident that if the broken key has not become too badly burned or otherwise objectionably hardened, it may be employed by having a hole 8 bored therein, as shown in Fig. 2, and a pin inserted,- but for ordinary convenience and quick repairs, the engineer would be provided with a number of additional previously constructed keys of the character embodying my invention, so that there would be no necessity at the time --of the repairs for doing any boring or other machine work.

In a plying my invention to a stoker grate w en making repairs, it will be underwearer stood that as the endless chain of carrier bars with their keys pass upward at the forward part of the stoker, they are freely exposed, and it is at this lace that the replacements are readily per ormed. For such replacement, it is only necessary to book my improved key into position upon the dove-tail portion of the bar by means of the lug 5 and then to drive in the pin 9, the operation taking only a very short period of time. T have shown the application of my invention to the rear end of the key, so that the pin 7 constitutes the equivalent of the lug 6 of a normal key, but it is manifest that my invention may be applied to the other portion of the key to constitute the equivalent of the lug 5, as the general construction would be identically the same as that shown, but ap plied to the forward portion of the key, instead of to the rear portion thereof. T find, however, in practice, that it is more con venient to apply the key to the rear end, as

shown, as it permits more keys to be applied in a given period during the exposure of the keys of the grate when rising in front of the stoker or feeding portion of the mechanism. This is an important feature, because, at times of the peak of the loads when hard firmg or steam is required, no interruption in the travel of the grate must be permitted and repairs should be made rapidly and effectively to prevent defective operation of the fire bed.

In the modified construction shown in F ig., 4:, the only difference from that shown in Fig. 2 is that the pin 7* which engages the dove-tail portion of the carrier bar is made as somewhat larger in diameter and is driven down into locking position by a small hardened steel pin 9 tightly fitting a corto which my invention is specially adapted.

The keys 3 and 3 constitute fuel supporting members of the grate as a whole and while if have, by way of example, illustrated my invention by applying the improvements to the fuel supporting members of a Coke stoker grate and generally known as keys, T do notlirnit myself to that particular form of fuel supporting members, as they may be otherwise made and movable with the carrier bar.

lit will now be apparent that T have devised a novel and useful construction which embodies the features of advantage enumerated as desirable, and while if have in the present instance shown and described the body part provided at its lower portion with a supporting surface terminating at one end in a lug adapted to engage a dove-tail support and also having an oblique hole extending downward from the upper surface of the body of the key said hole having its obliquity oppositely directed to the obliquity of the lug,'combined with anoblique locking pin fitting the oblique hole and said pin arranged at an angle to the engaging surface of the lug and forming therewith a dove-tail recess for engaging a dove-tail portion of the carrier bar.

2. The invention according to claim 1, wherein the pin is of greater length than the length of the hole in the key so that when the pin is initially extended above thekey, its lower part will be sufiiciently raised to permit the key to bepositioned upon the dove-tail portion of the carrier bar and when the key is driven downward its lower end will project beyond the body of the key to constitute an engaging portion equivalent to the lug of the key.

3. The invention according to claim 2, wherein the pin is of a. diameter relatively to the hole that it is frictionally held therein wherever driven in a rigid manner.

4. In a grate structure, the combination of a carrier bar having upon its upper portion a dove-tail bar structure, combined with a large number of keys having dovetail recesses upon their under portions fitting the dove-tail structure of the carrier bar and presenting at their upper portions grate surfaces, and one or more repair keys associated with and corresponding in general shape to the normal keys, said repair keys each havingits lower portion provided with a lug integral with its body portion for engagement with a portion of the dove-tail structure of the carrier bar and also having an oblique pin projecting downward at the bottom of the key in a direction opposite to the lug to project so that its. lower end constitutes a locking portion engaging the other part of the dove-tail structure of the carrier bar said pin frictionally held in the body of the repair key and adapted to be forcibly driven downward, whereby said repair keysmay be quickly substituted for broken or injured keys which have been disconnected from the carrier bar.

5. A carrier bar, combined with a fuel supporting member constituting a section'of the grate, said fuel supporting member resting upon the carrier bar and provided with an engaging portion therefor, and a locking pin extending downward through the fuel supporting member and frictionally held therein, said pin initially out of engagement with the carrier bar but adapted to be driven downward so that its lower end engages the carrier bar and together with the engaging portion of the fuel supporting member locks the said member firmly to the carrier bar.

In testimony of which invention, I hereunto set my hand. 7

GEORGE W. EDWARDS. 

